I. Hui Lee

Psychiatric morbidity and posttraumatic symptoms among earthquake victims in primary care clinics

Three months after the devastating Chi-Chi earthquake (magnitude of 7.3 on the Richter scale) struck the central area of Taiwan, 663 victims were screened for psychiatric morbidity at a local general hospital in a community mental health program. The rate of psychiatric morbidity as defined by the 12-item Chinese Health Questionnaire as greater than 4, was 24.5%. Posttraumatic symptoms were still prevalent. The rate of posttraumatic stress disorder was 11.3%, and the rate of partial PTSD was 32.0%. Variables associated with the presence of psychiatric morbidity and posttraumatic symptoms included female gender, old age, financial loss, obsessive trait, and nervous trait. A disproportionate use of mental health services (18%) was found, suggesting an urgent need to deliver mental health care to disaster victims at local medical settings. In addition, health care professionals who work with the earthquake victims need to be promptly and efficiently trained in mental health crisis intervention.

A study on the sleep quality of incoming university students.

This study was designed to examine the prevalence and the risk factors of poor sleep quality in 4318 incoming university students in Taiwan. The test battery comprised a self-administered structured questionnaire, including items related to personal medical history and lifestyle habits, the Measurement of Support Functions (MSF), Pittsburgh Sleep Quality Index (PSQI), Chinese Internet Addiction Scale-Revision (CIAS-R), neuroticism subscale of the Maudsley Personality Inventory (MPI), and the 12-item Chinese Health Questionnaire (CHQ-12). Of the total study population, 2360 students (54.7%) were classified into the poor sleep quality group, as defined by a PSQI score ≥6. Based on the results of multivariate logistic regression analysis, poor sleep quality was significantly associated with undergraduate students, female gender, skipping breakfast, tea drinking, a higher tendency toward internet addition, poor social support, higher neuroticism, and higher CHQ scores. Poor sleep quality is prevalent among incoming university students in Taiwan, and more work is needed on the identification of the factors influencing poor sleep, and in providing systematic education in the importance of sleep and time management skills to university students.

Decreased dopamine transporter availability in male smokers — A dual isotope SPECT study

INTRODUCTION Although the mesolimbic dopaminergic system has been shown to play a role in reinforcing tobacco smoking, results of imaging studies that examine the relationship between tobacco smoking and the central dopamine system remain discrepant. To delineate the role of tobacco addiction in central pre- and post-synaptic dopaminergic activities, we analyzed the central D2-family receptors, the dopamine transporters (DAT), and degrees of dependence in male smokers. METHODS Eleven male smokers and 11 healthy non-smokers were recruited. The striatal dopamine D2/D3 receptor availability was approximated using SPECT and [123 I] IBZM while the DAT availability was approximated using SPECT and [99m Tc] TRODAT-1. All of the smokers completed the Fagerström Test for Nicotine Dependence (FTND) and other related questionnaires. RESULTS A decrease in DAT availability in the striatum of male smokers is noted (p<05). However, the striatal D2/D3 receptor availability in male smokers does not differ from that of non-smokers. CONCLUSIONS These findings suggest that cigarette smoking may alter central dopamine functions in males, particularly at the pre-synaptic sites.

Greater availability of dopamine transporters in patients with major depression — A dual-isotope SPECT study

In order to explore the neuropathology of the pre- and post-synaptic dopamine neurons of patients with major depression, we examined striatal D(2)/D(3) receptor uptake and dopamine transporter (DAT) availability simultaneously in drug-free depressed patients using a dual-isotope single photon emission computed tomography (SPECT) imaging technique. Ten unmedicated patients with unmediated depression and ten healthy controls were recruited. The striatal dopamine D(2)/D(3) receptor availability was measured using SPECT and [(123)I] IBZM, while DAT was measured using SPECT and [(99m)Tc] TRODAT-1. The symptom changes of the drug-free patients were reassessed after a 4-week antidepressant treatment. DAT binding in the patient group were significantly higher than in control group. That was not the case, however, for striatal D(2)/D(3) receptor availability. Pre-treatment striatal DAT availability correlated only marginally with changes in the Hamilton Depression Rating Scale after 4 weeks of treatment. Central dopamine functions may be altered in patients with major depression, particularly in the pre-synaptic sites.

Correlation between fine motor activity and striatal dopamine D2 receptor density in patients with schizophrenia and healthy controls.

Striatal dopamine D2 receptor density is an important indicator of many neuropsychiatric disorders and also of motor activity. This study examined the relationship between a fine motor task (finger tapping test, FTT) and striatal D2 dopamine receptor density by examining 20 healthy volunteers and 20 schizophrenic patients. Striatal D2 receptor density was determined with single photon emission computed tomography using [123I]IBZM (iodo-benzamide). The correlation between the FTT score and striatal D2 receptor density was statistically significant not only in the patient group but also in healthy controls. The FTT scores and striatal D2 receptor density were lower in medicated patients than that in healthy controls. Compared with the Simpson-Angus Scale scores, the FTT scores were more strongly associated with striatal D2 receptor density. The use of neuroleptic medication seemed to influence the associations between FTT scores and striatal D2 receptor density in the patient group. The FTT scores and striatal D2 receptor density were age-sensitive in healthy controls. FTT may be a more sensitive tool for detecting neuroleptic-induced motor impairment in patients with schizophrenia. The sensitivity of the FTT to age and neuroleptic effects may be explained in part by a decline in dopamine D2 density.

A Placebo-Controlled Trial of Dextromethorphan as an Adjunct in Opioid-Dependent Patients Undergoing Methadone Maintenance Treatment

Background: Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT). Methods: Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor–β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect. Results: After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different. Conclusions: We provide evidence—decreased concomitant heroin use—of low-dose add-on DM’s efficacy for treating opioid-dependent patients undergoing MMT.

Availability of dopamine and serotonin transporters in opioid-dependent users—a two-isotope SPECT study

Rationale and objectiveThe aims of this study were to examine the differences between 32 opioid-dependent users treated with a very low dose of methadone or undergoing methadone-free abstinence and 32 controls.MethodsSPECT analysis using [99mTc] TRODAT-1 to assess striatal dopamine transporter (DAT) availability and [123I] ADAM to assess midbrain serotonin transporter (SERT) availability were performed.ResultsLower striatal DAT and midbrain SERT availabilities were noted in low-dose methadone users. History of metamphatamine use was associated with the lower striatal DAT. The striatal DAT of methadone-free abstainers was also lower than controls. The midbrain SERT availability tended to be higher in the methadone-free abstainers than the low-dose methadone users. The severity of depressive symptoms was negatively correlated with midbrain SERT availability in the opioid users.ConclusionThe availability of striatal DAT tended to be, and the availability of midbrain SERT was, lower in the opioid users. History of metamphatamine use may confound the difference in straital DAT between controls and opioid users, as midbrain SERT and depressive symptoms are also associated with opioid use and abstinence.

Association between cognitive performance and striatal dopamine binding is higher in timing and motor tasks in patients with schizophrenia

The basal ganglia have received increasing attention with regard to their role in time pacing, motor function and other components of cognition. The aim of this study was to test whether the finer the motor activity and/or time perception performance were, the higher the striatal dopamine D(2) binding would be. Single photon emission computed tomography (SPECT) with [(123)I]iodobenzamide (IBZM) was performed to measure striatal D(2) receptor densities. A battery of neuropsychological tests, including the Wisconsin Card Sorting Test (WCST), the finger tapping test (FTT), and an attention test, was performed by patients with schizophrenia. Results indicated a strong correlation between the FTT score and striatal D(2) receptor binding. Neuroleptic dosage plays an important role in the relationship between cognitive tasks and striatal dopamine receptor densities. In addition, the striatal D(2) receptor density is more significantly correlated with attentional tests that consider the time effect than those that do not. Among the three tests performed, the WCST was least significantly correlated with striatal D(2) receptor densities. A decrease in striatal dopamine D(2) receptor density seems to be associated with impaired performance on optimal timing tasks and motor processing in patients with schizophrenia.

Correlation between different memory systems and striatal dopamine D2/D3 receptor density: a single photon emission computed tomography study.

OBJECTIVE Although studies have indicated that the human basal ganglia have a specific role in different memory systems, the functional significance of the striatal dopamine activities for the basal ganglia remains less clear. This study assessed the relationship between measures of striatal dopamine activities and indices of different memory systems in healthy individuals. METHOD Single photon emission computed tomography and [123I]IBZM (iodobenzamide) were used to assess the striatal dopamine D2/D3 receptor density in 62 healthy volunteers aged between 19 and 61 years. All subjects underwent a Wechsler Memory Scale-Revised test. RESULTS Dopamine D2/D3 receptor densities in the striatum decline with age. Stepwise regression analysis showed that verbal delayed recall and working memory account for most of the variance in dopamine D2/D3 measurements. These relationships remain significantly after controlling for age effects. CONCLUSIONS Brain striatal dopamine activities are also significantly associated with various memory systems, in addition to motor functions. This may explain why patients with neuropsychiatric disorders may have both memory and motor impairments.

Correlation between striatal dopamine D2 receptor density and neuroticism in community volunteers

The central dopaminergic system, as well as the central serotonergic system, has been reported to be correlated with higher neuroticism. The present study examined the relationship between striatal dopamine D(2) receptor density and neuroticism. Neuroticism was assessed with the Maudsley Personality Inventory, and psychiatric morbidity was evaluated with both the Mini International Neuropsychiatric Interview and the Hamilton Depression Rating Scale (HAM-D). Single photon emission computed tomography with [(123)I]iodo-benzamide was used to measure striatal dopamine D(2) receptor density. HAM-D scores and psychiatric morbidity in high-neuroticism individuals were higher than in low-neuroticism individuals. Moreover, striatal dopamine D(2) receptor densities were significantly correlated with the neuroticism score of the 41 subjects. The central dopaminergic system may play an important role in the neurobiological characteristics of neuroticism.